Records |
Author ![sorted by Author field, descending order (down)](img/sort_desc.gif) |
Alfonso, V.I.; Bejarano, C.; Beltran Jimenez, J.; Olmo, G.J.; Orazi, E. |
Title |
The trivial role of torsion in projective invariant theories of gravity with non-minimally coupled matter fields |
Type |
Journal Article |
Year |
2017 |
Publication |
Classical and Quantum Gravity |
Abbreviated Journal |
Class. Quantum Gravity |
Volume |
34 |
Issue |
23 |
Pages |
235003 - 20pp |
Keywords |
modified gravity; metric-affine theories; torsion; non-minimal couplings |
Abstract |
We study a large family of metric-affine theories with a projective symmetry, including non-minimally coupled matter fields which respect this invariance. The symmetry is straightforwardly realised by imposing that the connection only enters through the symmetric part of the Ricci tensor, even in the matter sector. We leave the connection completely free (including torsion), and obtain its general solution as the Levi-Civita connection of an auxiliary metric, showing that the torsion only appears as a projective mode. This result justifies the widely used condition of setting vanishing torsion in these theories as a simple gauge choice. We apply our results to some particular cases considered in the literature, including the so-called Eddington-inspired-Born-Infeld theories among others. We finally discuss the possibility of imposing a gauge fixing where the connection is metric compatible, and comment on the genuine character of the non-metricity in theories where the two metrics are not conformally related. |
Address |
[Alfonso, Victor I.] Univ Fed Campina Grande, Unidade Acad Fis, BR-58109970 Campina Grande, PB, Brazil, Email: viafonso@df.ufcg.edu.br; |
Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0264-9381 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:000414726500001 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
3353 |
Permanent link to this record |
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Author ![sorted by Author field, descending order (down)](img/sort_desc.gif) |
Alencar, G.; Estrada, M.; Muniz, C.R.; Olmo, G.J. |
Title |
Dymnikova GUP-corrected black holes |
Type |
Journal Article |
Year |
2023 |
Publication |
Journal of Cosmology and Astroparticle Physics |
Abbreviated Journal |
J. Cosmol. Astropart. Phys. |
Volume |
11 |
Issue |
11 |
Pages |
100 - 23pp |
Keywords |
Exact solutions; black holes and black hole thermodynamics in GR and beyond; GR black holes; modified gravity; quantum black holes |
Abstract |
We consider the impact of Generalized Uncertainty Principle (GUP) effects on the Dymnikova regular black hole. The minimum length scale introduced by the GUP modifies the energy density associated with the gravitational source, referred to as the Dymnikova vacuum, based on its analogy with the gravitational counterpart of the Schwinger effect. We present an approximated analytical solution (together with exact numerical results for comparison) that encompasses a wide range of black hole sizes, whose properties crucially depend on the ratio between the de Sitter core radius and the GUP scale. The emergence of a wormhole inside the de Sitter core in the innermost region of the object is one of the most relevant features of this family of solutions. Our findings demonstrate that these solutions remain singularity free, confirming the robustness of the Dymnikova regular black hole under GUP corrections. Regarding energy conditions, we find that the violation of the strong, weak, and null energy conditions which is characteristic of the pure Dymnikova case does not occur at Planckian scales in the GUP corrected solution. This contrast suggests a departure from conventional expectations and highlights the influence of quantum corrections and the GUP in modifying the energy conditions near the Planck scale. |
Address |
[Alencar, G.; Olmo, Gonzalo J.] Univ Fed Ceara, Dept Fis, Caixa Postal 6030,Campus Pici, BR-60455760 Fortaleza, Ceara, Brazil, Email: geova@fisica.ufc.br; |
Corporate Author |
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Thesis |
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Publisher |
IOP Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1475-7516 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
WOS:001121623400017 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ pastor @ |
Serial |
5868 |
Permanent link to this record |
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Author ![sorted by Author field, descending order (down)](img/sort_desc.gif) |
Agullo, I.; Navarro-Salas, J.; Olmo, G.J.; Parker, L. |
Title |
Hawking Radiation by Kerr Black Holes and Conformal Symmetry |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review Letters |
Abbreviated Journal |
Phys. Rev. Lett. |
Volume |
105 |
Issue |
21 |
Pages |
211305 - 4pp |
Keywords |
|
Abstract |
The exponential blueshift associated with the event horizon of a black hole makes conformal symmetry play a fundamental role in accounting for its thermal properties. Using a derivation based on two-point functions, we show that the full spectrum of thermal radiation of scalar particles by Kerr black holes can be explicitly derived on the basis of a conformal symmetry arising in the wave equation near the horizon. The simplicity of our approach emphasizes the depth of the connection between conformal symmetry and black hole radiance. |
Address |
[Agullo, Ivan; Parker, Leonard] Univ Wisconsin, Dept Phys, Milwaukee, WI 53201 USA |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
0031-9007 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000284407400004 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
322 |
Permanent link to this record |
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Author ![sorted by Author field, descending order (down)](img/sort_desc.gif) |
Agullo, I.; Navarro-Salas, J.; Olmo, G.J.; Parker, L. |
Title |
Acceleration radiation, transition probabilities and trans-Planckian physics |
Type |
Journal Article |
Year |
2010 |
Publication |
New Journal of Physics |
Abbreviated Journal |
New J. Phys. |
Volume |
12 |
Issue |
|
Pages |
095017 - 18pp |
Keywords |
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Abstract |
An important question in the derivation of the acceleration radiation, which also arises in Hawking's derivation of black hole radiance, is the need to invoke trans-Planckian physics in describing the creation of quanta. We point out that this issue can be further clarified by reconsidering the analysis in terms of particle detectors, transition probabilities and local two-point functions. By writing down separate expressions for the spontaneous-and induced-transition probabilities of a uniformly accelerated detector, we show that the bulk of the effect comes from the natural (non-trans-Planckian) scale of the problem, which largely diminishes the importance of the trans-Planckian sector. This is so, at least, when trans-Planckian physics is defined in a Lorentz-invariant way. This analysis also suggests how one can define and estimate the role of trans-Planckian physics in the Hawking effect itself. |
Address |
[Agullo, Ivan; Olmo, Gonzalo J.; Parker, Leonard] Univ Wisconsin, Dept Phys, Milwaukee, WI 53201 USA, Email: ivan.agullo@uv.es |
Corporate Author |
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Thesis |
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Publisher |
Iop Publishing Ltd |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1367-2630 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000284766400006 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
318 |
Permanent link to this record |
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Author ![sorted by Author field, descending order (down)](img/sort_desc.gif) |
Agullo, I.; Navarro-Salas, J.; Olmo, G.J.; Parker, L. |
Title |
Reply to "Comment on 'Insensitivity of Hawking radiation to an invariant Planck-scale cutoff' '' |
Type |
Journal Article |
Year |
2010 |
Publication |
Physical Review D |
Abbreviated Journal |
Phys. Rev. D |
Volume |
81 |
Issue |
10 |
Pages |
108502 - 3pp |
Keywords |
|
Abstract |
We clarify the relationship between the conclusions of the previous Comment of A. Helfer [A. Helfer, preceding Comment, Phys. Rev. D 81, 108501 (2010)] and that of our Brief Report [I. Agullo, J. Navarro-Salas, G. J. Olmo, and L. Parker, Phys. Rev. D 80, 047503 (2009).]. |
Address |
[Agullo, Ivan; Olmo, Gonzalo J.; Parker, Leonard] Univ Wisconsin, Dept Phys, Milwaukee, WI 53201 USA |
Corporate Author |
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Thesis |
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Publisher |
Amer Physical Soc |
Place of Publication |
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Editor |
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Language |
English |
Summary Language |
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Original Title |
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Series Editor |
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Series Title |
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Abbreviated Series Title |
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Series Volume |
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Series Issue |
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Edition |
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ISSN |
1550-7998 |
ISBN |
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Medium |
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Area |
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Expedition |
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Conference |
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Notes |
ISI:000278146700144 |
Approved |
no |
Is ISI |
yes |
International Collaboration |
yes |
Call Number |
IFIC @ elepoucu @ |
Serial |
430 |
Permanent link to this record |